There is no highest common multiple of 56, 98 and 168. Their highest common factor, which you may have meant, is 14.
It is: 14
The GCF is 14.
The GCF is 14.
The GCF is 14.
The GCF of 56, 98, and 126 is 14.
The GCF of 56, 98, and 108 is 2
The Greatest Common Factor of 42, 56, 98: 14
14
7 is the highest common factor of 21, 77 and 91.
The GCF is 14.
It is: 14